This invention relates to a latch operating device of the type making use of a spindle of the form requiring particular exact side positioning orientation relative to the latch being operated and regardless of the latch side at which such operating mechanism is positioned. According to certain of the principles of the present invention, a unique form of connection is provided between the spindle and its latch operating mechanism within which it is integrated such that the spindle is selectively positionable with the latch operating mechanism in either of two opposite required and positive operational positions, thereby very simply selectively adapting the assembly to overall positioning for properly operating the particular latch from either side of the door within which it is mounted without the use of substitute parts. Furthermore, due to the inherent broad structure of the unique form of spindle connection, the overall latch operating mechanism may be greatly simplified into a positively operable form requiring less complexity and reducing fabrication costs, while still maintaining an increased efficiency of operation.
A certain prominent group of prior door latch constructions require that the spindle partially rotating to operate the same be in a particular same positioning orientation relative to the latch being operated regardless of the side of the door from which the spindle principally extends and at which the latch operating mechanism with which the spindle is operationally connected is mounted. The particular spindle shapes are generally half-round spindles and such spindles with the particular form of latch that they operate much always be positioned with the generally semi-circular outer surfaces thereof extending in a particular latch longitudinal direction. This meant that if the latch operating mechanism was mounted at one side of the door with the spindle extending therefrom into operational engagement with the latch or if the latch operating mechanism with its spindle was mounted at the opposite side of the door, the spindle was required to be positioned facing in the exact same longitudinal direction regardless of the particular door side mounting. The overall result was that two different latch operating device models were required, despite the fact that the only differences therebetween were the particular positioning of the spindles relative to their latch operating mechanisms.
In more recent times, in order to eliminate the foregoing problem, certain modifications were made in the manner of mounting the spindles with their latch operating mechanisms so as to permit selective complete disassembly of the spindles from their latch operating mechanisms, reverse positioning of the spindles and then the reassembly with their latch operating mechanisms. In this manner, it was possible to supply merely a single model of the latch operating devices and they could be altered through properly instructed procedure at the site of installation for adapting the same to the particular door side positioning. Such modified construction is shown in the prior U.S. Pat. No. 3,704,036, issued Nov. 28, 1972 and entitled "THUMB LEVER ACTUATED LATCH OPERATING DEVICE."
Referring to the prior U.S. Pat. No. 3,704,036, and regardless of whether or not the particular latch operating mechanism associated with the half-round spindle is thumb lever actuated or otherwise, the half-round spindle is connected to the latch operating mechanism through a hollow, cylindrical retainer having spring actuated, alternate, semi-circular sockets formed therein. Thus, if the particular latch operating mechanism is to be mounted at one side of the door, the half-round spindle is inserted into the proper socket of the spindle retainer so that proper positioning orientation is obtained with the latch within the door, and if the latch operating mechanism is to be mounted at the other side of the door, the half-round spindle is merely selectively disengaged from the one spindle retainer socket and inserted in the other or opposite socket for such proper latch positioning orientation. With either spindle retaininer positioning, the latch operating mechanism is operable to partially rotate the spindle retainer and its socket retained spindle for the usual actuation of the engaged latch.
Although the alternate spindle retainment arrangement as described effectively solves the problem of the requirement that alternate latch operating devices be provided for the alternate door side positioning and provided a single model replacing the two, certain difficulties have been experienced therewith. Obviously, since the spindle is retained in the spindle retainer sockets are merely a relatively short end portion thereof and must extend from the latch operating mechanism for a moderate distance to pass through and be operationally engaged with the latch to be operated, the spring pressed engagement of the half-round spindle in the particular socket of the spindle retainer is not always sufficiently secure. Keeping in mind that the sole means for transferring the intended rotational motion of the latch operating mechanism into the longitudinal motion of latch operation is the spindle, any failure in this motion transfer arrangement will cause complete failure of latch operation. Furthermore, with this modified spindle retainer arrangement, unless the end of the half-round spindle is totally properly inserted into the particular spindle retainer socket, the train of motion transfer can again be accidentally lost.
Thus, although the alternate spindle positioning concept with a single latch operating mechanism is highly desirable to retain, the manner of selectively connecting the spindle end in its alternate position requires improvement. In addition, the alternate spindle positioning concept can be further improved and made more problem free by offering the concept in a construction which does not depend upon complete assembly separation and reassembly in the alternate position. Rather, the alternate positioning of the spindle should be in a form of a more positive, foolproof nature so that if the latch operating mechanism including the spindle originally properly operates the latch, it cannot fail by disassembly after a period of time.
Further referring to the prior U.S. Pat. No. 3,704,036, in the particular instance where the latch operating device is of the thumb lever actuating type, various improvements in the complexity thereof are warranted. Reviewing the construction disclosed in the patent, a vertically pivotal thumb lever end wise engages an actuating block or yoke vertically slideable in a slide frame. The yoke, in turn, engages and vertically pivots an actuating lever which likewise end engages and vertically reciprocates a slide bar. Finally, the slide bar is engaged with a radial crank arm attached to the previously described spindle retainer and latch engaged spindle.
In operation, pivotally depressing the thumb lever vertically slideably raises the yoke which pivots the actuating lever in an arc vertically upwardly. The upward movement of the actuating lever end moves the slide bar upwardly forcing the radial crank arm to partially rotate the spindle retainer and thereby partially rotate the spindle to actuate the latch. In basic effect, these variously interconnected elements transform the vertically pivotal motion of the thumb lever into the partial rotational motion of the spindle retainer and spindle for carrying out the actuation of the latch. Although this motion conversion is of a relatively complex nature requiring relatively complex element connections, improvement of the same is warranted as hereinbefore stated.